American Medical Association Family Medical Guide - American Medical Association [748]
Exophthalmos
Exophthalmos is a condition in which one or both eyeballs bulge forward, exposing an abnormally large part of the front of the eye (see page 128). The most common cause of the condition is Graves’ disease (see page 901), an autoimmune disorder that causes the thyroid gland to become overactive. Other possible causes of exophthalmos include a tumor behind the eyeball (see previous page) or inflammation of the tissue behind the eyeball (orbital cellulitis; see next page).
Symptoms
In exophthalmos, the eyes tend to feel dry. Eye movement may be restricted, which can cause double vision. In severe cases, the eye is pressed so far forward that the eyelids may not close completely and the front of the eye may become dry and feel gritty, causing pain and blurred vision.
Diagnosis
A diagnosis of exophthalmos is based on the symptoms, a health history, a physical examination, and an examination of the eye, especially the orbit (the bony socket in which the eyeball sits). The doctor may order blood tests and recommend an ultrasound (see page 111), a CT scan (see page 112), or an MRI (see page 113) to help determine the cause.
Treatment
If exophthalmos is caused by Graves’ disease, the doctor will treat Graves’ disease. However, successful treatment of Graves’ disease may not eliminate the bulging, and the ophthalmologist may prescribe corticosteroid drugs to relieve the inflammation and pain. If there is loss of vision, radiation therapy (see page 23) may be recommended.
An ophthalmologist may recommend surgery on the eyelids to help protect the exposed eyeball and prevent corneal ulcers (see page 1037) from developing. In severe cases, surgery may be necessary to increase the orbital space and relieve the pressure behind the eyeball. If a tumor is detected, the ophthalmologist will probably recommend a biopsy (in which samples of cells are taken from the tumor and examined under a microscope), or surgery to remove the tumor. Depending on the results of the biopsy, the doctor may recommend radiation therapy, chemotherapy (see page 23), or both.
Orbital Cellulitis
Orbital cellulitis is inflammation of the soft tissue of the orbit (the bony socket in the skull that contains the eyeball). The condition usually occurs when bacteria from a sinus infection (see page 651), from a penetrating injury to the orbit, or from a boil (see page 1060) spread and infect the orbit. There is a risk that the infection could spread to the brain and cause an abscess (a pus-filled cavity surrounded by inflamed tissue) or meningitis (see page 692), a potentially life-threatening infection of the meninges (the membranes that surround and protect the brain and spinal cord).
Symptoms
In orbital cellulitis, the swollen tissue pushes on the eyeball and causes it to bulge forward in the orbit (exophthalmos; see previous page). Other possible symptoms of orbital cellulitis include redness and severe pain in the eye, swollen eyelids, difficulty moving the eye, impaired vision in the eye, and fever. The eye may produce a discharge of pus. Pressure on or inflammation of the blood vessels and nerves that supply the eye may lead to blurred vision or blindness.
Diagnosis and Treatment
A diagnosis of orbital cellulitis is based on the symptoms and an examination of the affected eye. The ophthalmologist (eye MD) will order blood tests to determine the cause of the infection and a CT scan (see page 112) of the affected orbit to determine the extent of the infection.
Treatment of orbital cellulitis consists of high doses of antibiotics given intravenously (through a vein). If infected sinuses are causing the problem, the doctor may recommend surgery to drain the sinuses. If the infection causes abscesses (pockets of pus) to form in the orbit, the ophthalmologist may recommend surgery to drain the pus from the abscesses.
Misaligned Eyes
Normally aligned eyes move together and look in the same direction at the same